Air pollution control through kiln recycling by-pass dust in a cement factory
Over the centuries, air pollution has increased from a local nuisance to a global problem (Emberlin 1998). Cement industry is one of the most important and strategic industries in Iran. However, its air pollution has been a serious problem. The primary related pollution is dust, which industrial countries have allocated tremendous efforts in reducing its volume. Dust in different stages of a production line of cement is dispersed and by suitable dust catcher will be collected. The collected dust, often from combination point of view is similar to circulation materials at the same area of process and for this reason is returned to the production line (Mohsenzadeh, et al., 2006). In the past, cement kiln dust was kept as industrial wastage, but recently it is emphasized for its application, because a considerable amount of energy has been to be paid for its preparation, calcinations and so discarding it, bring out wastage of energy and cost. On the other hand, due to consideration of high volume of the collected dust, a lot of costs were allocated by collection and destroying it, due to have some special chemical compound which, has adverse environmental effects (Chehregani, 2005). Different scientific and technical sources and the following applications have been introduced. As reinforcement in asphalt concretes, it helps its high strength and life (Debell, M., 1997), as it contains materials such as K2O, CaO,Na2O helps to stabilization of sewage sludge (Holdereank Seminar, 2000). By pass dust of rotating kiln due to fine granulation can absorb SO2 from power supplies (Tettmar, B. et al., 2003).